Optical spectroscopy is widely used for various analytical techniques and for experimental techniques in applied and basic research. Experiments utilizing spectroscopy are performed to determine optical constants of material samples as well as to establish the chemical and physical composition of those material samples. However, optical spectroscopy, particularly in the mid-infrared energy region, is still limited by: (1) sensitivity of the detectors utilized which have a comparatively small dynamic range; (2) anomolies resulting from surface variations and/or inhomogenities; and (3) changes in the indices of refraction which appear to change the absorbtiveness of the sample materials.
In the past, various spectroscopic apparatus has been developed to vary certain parameters to determine the optical constants of a material by the variations detected. Alternatively, spectroscopic techniques have been used to determine absorbtivities of materials. In fact, libraries of books and electronic media exist which uniquely identify pure materials by means of their absorbtions of electromagnetic radiations at various frequencies.
Unfortunately, the resulting spectra derived by the use of current spectroscopic apparatus or spectroscopic sampling techniques typically require that the materials be analyzed in a form which requires extensive sample preparation or even sample destruction. Such sample preparation normally utilizes a sealed cell or a KBR pressed technique. In addition, current spectroscopic apparatus may require the sample to be moved from instrument to instrument in order to obtain the full range of spectroscopic tests required. Alternatively, the instrument used may have to be temporarily modified to utilize additional peripheral or optional equipment to perform the full range of spectroscopic analysis. The sample preparation and variations in equipment require additional time to be expended to obtain the spectroscopic analysis results and may adversely effect those results due to the partial or total destruction of the sample and/or to the variations between equipment.